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Call for ContributionsHETEROCYCLES Special Issue Vol. 99 in honor of Professor Tohru Fukuyama on 70th Birthday

Submission deadline: September 10, 2018
On the occasion of Professor Tohru Fukuyama's 70th birthday, HETEROCYCLES editorial office is planning to publish special anniversary issue on April 1, 2019 as Vol. 99. Authors are invited to submit their work to this topical issue.
Authors wishing to submit their manuscript should contact editorial office via e-mail by the end of May, 2018. Manuscript should reach the editorial office no later than September 10, 2018.
Contact: submit@heterocycles.com

March 5, 2018

Heterocycles Award
HETEROCYCLES is pleased to announce Heterocycles Award.
In recognition of an outstanding oral presentation at the 47th Congress of Heterocyclic ChemistrySee more

December 13, 2017

Call for ContributionsHETEROCYCLES Special Issue Vol. 97 in honor of Professor Kiyoshi Tomioka on 70th Birthday

Submission deadline: February 15, 2018
On the occasion of Professor Kiyoshi Tomioka's 70th birthday, HETEROCYCLES editorial office is planning to publish special anniversary issue on September 1, 2018 as Vol. 97. Authors are invited to submit their work to this topical issue.
Authors wishing to submit their manuscript should contact editorial office via e-mail by the end of November, 2017. Manuscript should reach the editorial office no later than February 15, 2018.
Contact: submit@heterocycles.com

■ A New Approach for Construction of Quarternary Chiral Centers: Preparation of α-Branched Serine Derivatives

Abstract

In the presence of a Lewis acid, the Michael-type reaction of (3R)-5-tert-butyldimethylsiloxy-3-phenyl-1H-pyrrolo[1,2-c]oxazole (1) with nitro olefins smoothly occurred to give 7a-alkylated pyrrolo[1,2-c]oxazol-5-ones (2) in good yields. The products (2) were successfully transformed to a α-branched serine derivatives via reductive denitration followed by lactam-ring cleavage.

■ The First Total Synthesis of Bufobutanoic Acid by Two Routes Based on Nucleophilic Substitution Reaction on Indole Nucleus

Abstract

Regioselective nucleophilic substitution reaction of 1-hydroxytrypta- mines led to establish two novel routes for the first synthesis of bufobutanoic acid. An effective synthesis of 5-benzyloxytryptamine from tryptamine is also reported.

Abstract

The magnesium enolates, generated by treatment of acyclic (1) and cyclic tertiary amides (4) with a (diisopropylamino)magnesium reagent, reacted efficiently with nitriles (2) to afford the corresponding β-aminoacrylamides (3) and α-(α-aminoalkylidene)lactams (5). The formation of α-(2-pyrrolidinylidene)lactams (7) from the reactions of N-methyl-2-pyrrolidone and N-methyl-2-piperidone with a γ-cyanopropyl p-toluenesulfonate (6) is also described.

Abstract

The development of a general strategy for the construction of heteroanthracyclinones based on an annelation reactions of the anion generated from 6-ethylsulfonyl-3-phenylfuro[3,4-d]isoxazol-4(6H)-one (3) with quinone monoketals is described.

Abstract

Aglaiastatin, an antitumor alkaloid, contains fused pentacyclic system, including a benzofurocyclopentane system and a unique pyrrolopyrimidinone skeleton. In this study, synthesis of a keto aldehyde intermediate, a key intermediate in a previously reported procedure for total synthesis, was accomplished via Pd(0)-mediated benzofuran ring closure. Thus, a formal total synthesis of aglaiastatin was achieved.

Abstract

Mechanisms for the reaction of 3-hydrazono-1,1,1-trifluoro-2- alkanons (1) to 4,5-bis(trifluoromethyl)pyridazines (2) in the presence of TFA are discussed on the basis of the 6-31G* level ab initio calculations. The results indicate a concerted [4+2] cycloaddition reaction of protonated 1 to be a key step for this reaction.

Abstract

A novel series of ethylenic naphth[2,3-d]oxazole-4,9-diones was synthesized via an SRN1 mechanism from the 2-chloromethylnaphth[2,3-d]oxazole-4,9-dione. This mechanism was confirmed by the inhibitory effects of the use of dark, bubbling oxygen, cupric chloride, p-dinitrobenzene and TEMPO.

■ Transformation of 5,6,7,8-Tetrahydro-2H-1-benzopyran-2,8-diones with Hydrazines and Hydrazoic Acid: Synthesis of 8-Hydrazono-5,6,7,8-tetrahydro-2-oxo-2H-1-benzopyrans, Pyrano[2,3-c]azepines and Pyrido[2,3-c]azepines

Abstract

N-(5,6,7,8-Tetrahydro-2,5-dioxo-2H-1-benzopyran-3-yl)-benzamide (1a) reacts with nitrogen-containing nucleophiles (2) (hydrazines and hydroxylamine) to give the corresponding 8-hydrazono derivatives (3a-i) and the related hydroxyimino derivative (3j). The action of hydrazoic acid on 1a-b or 3a-b and 3e resulted in the formation of pyrano[2,3-c]azepines (4a-b). The pyranoazepine (4a) can be debenzoylated to 4b or transformed into pyrido[2,3-c]azepines (5a-b).

■ An Unprecedented 1,8a-Bond Fission of an N -Formyl-1,2,3,4-tetrahydroisoquinoline Derivative under a Nitration Condition

Abstract

An unprecedented bond fission between the 1 and 8a positions of an N-formyl-1,2,3,4-tetrahydroisoquinoline derivative was observed under nitration conditions using nitric acid and acetic acid. The structures of the products and the proposed reaction mechanism were also described.

Abstract

Treatment of α,β-unsaturated ketones (I) with malononitrile in presence of ammonium acetate afforded 2-amino-4,6-diarylnicotinonitriles (II) which reacted with aq. alc. KOH, CS2 (pyridine), CS2 (EtOH/NaOH), phenyl isothiocyanate and guanidine hydrochloride to yield the corresponding heterocyclic products (III-VII) respectively. When I was allowed to react with cyanoacetanilide, ethyl chloroacetate, benzyl cyanide, 4-chlorobenzaldehyde and potassium cyanide, it gave the Michael adducts (VIII-XII). Fusion of XIb with hydrazine hydrate afforded XIII whereas treatment of XIb with hydrazine hydrate and/or hydroxylamine hydrochloride gave XIVa and b respectively. The evaluation of the minimal inhibitory concentration (MIC) of some of the synthesized compounds was carried out.

■ A Facile Synthesis of 1-Alkyl-7-azaisatins

Abstract

1-Alkyl-7-azaisatins are synthesized from the reaction of 1-alkyl-7-azaindoles with bromine in dichloromethane and subsequent oxidation with N-bromosuccinimide - dimethyl sulfoxide reagent. 1-Alkyl-7-azaindoles are readily available in high yields from the reaction of sodium salt of 7-azaindole with the appropriate alkyl halides in dimethylacetamide.

*Chemistry Department, Faculty of Science, University of Jordan, Amman, Jordan

Abstract

The reaction of (D)-3-acetyl-5-benzyl-1-phenyl-4,5-dihydro-1,2,4-triazin-6-one oxime (2) with nickel acetate in refluxing ethanol afforded the respective square planar Ni(II) complex. This is evidenced from an X-Ray study which reveals that the Ni(II) ion is coordinated to the ring N(4) and oxime nitrogen atoms. The crystallographic data of the complex (3) also unravelled that the nickel-complexation has led to the formation of one π-bond across the N(14)-C(15) bond and one σ-bond between a benzylic carbon atom of one ligand and the chiral (C5)carbon atom of the other ligand in the bis-ligand complex (3). Evidently, the complexed Ni(II) ion plays a template effect role in initiating such a cascade of π- and σ-bond forming reactions. 1H-, 13C-NMR and FD-MS spectral data of 3 are in full agreement with its molecular structure.

Abstract

A one-step synthesis of titled compounds from the reaction of α-allyl-α-cyano-o—tolunitrile with lithium amides and alkylithiums is described. The reaction of lithiated primary alkyl amines, allkyl- and aryllithiums at -78°C gave 1-substituted 4-([E]-1-propenyl)-3-aminoisoquinolines, whereas lithiated cyclic amides and 3-dimethylaminopropyl amide under similar conditions afforded 1-substituted 4-allyl-3-aminoisoquinolines. 1-Substituted 4-([E]-1-propenyl)-3-aminoisoquinolines were obtained as major product when reactions of the lithiated cyclic amides were performed at room temperature for 24 h. An explanation in terms of the effect of 4-substituents on the acidity of the α-methylene hydrogens is given.

■ Synthesis of 2,2-Dimethyl-2H -chromenes

Abstract

In the present review article, the most important procedures developed and utilized for the synthesis of 2,2-dimethyl-2H-chromenes are compiled and discussed. Special emphasis is layed on the most convenient and most important methods, viz. the dehydration of 2,2-dimethyl-4-hydroxychromans or the thermal rearrangement of phenyl propargyl ethers. However, less general and/or special procedures are critically discussed. Examples for the synthesis of nitrogen and sulfur analogues of 2,2-dimethyl-2H-chromenes have also been included.